Carter tries to figure out what a strange device found in Merlin’s cave does, after Dr. Lee failed to figure it out after six months. Carter finds something interesting, which unfortunately causes her and Mitchell to be transported to an alternate dimension. They can see and hear those around them, but no one can hear or see the two.

Teal’c, meanwhile, goes with SG-12 on a mission to check on the Sodan, after a distress message is received. Once there, they find Volnek has been affected by a Prior and is now killing everyone in his group in a crazed frenzy and madness, after actually having died.

The two story lines converge when Mitchell decides to go in his “out of sync” state with a second SG team set to rescue Teal’c and SG-12.

Recap

The Sodan were apparently destroyed by the Ori in this episode. A Prior encountered Volnek, killed him, then revived him using the same technology used by the Telchak reanimation device found in "Evolution." Then Volnek proceeded to kill every Sodan man woman and child, with the exception of Lord Haikon.

This episode marks a similarity to the season 3 episode "Crystall Skull," in that it deals with Daniel [as well as Lt. Col. Carter and Mitchell] going out of phase yet again.

The reference is to Patrick Swayze and to the movie Ghost, which stared Patrick Swayze. Mitchell also says they need a “Whoopi,” referring to Whoopi Goldberg, who also starred in Ghost, and referrers to someone who can see those that can’t be seen by others, as in ghosts.